About This Release

The Voice Switch Service Module (VXSM) product is supported by the MGX 8880 Media Gateway and the MGX 8850 Multiservice Switch. Refer to their respective release notes for platform and version level support guidelines.

Note To verify that you have the latest version of Cisco IOS required to support the new features included in this release, please check Cisco IOS availability status at Cisco.com.

VXSM implements a fax negotiation spoof that forces the SG3 fax machines to send the faxes over T.38 Group 3 (G3) modulations.

The following commands were modified to support this feature:

•addfaxprof

•cnffaxprof

•dspfaxprof

CLI and SNMP Support for Number of Active and Emergency Calls

With H.248, display counters are used to obtain information about the number of active and emergency voice calls that have been placed during a specified period of time. These counters are displayed at gateway level, virtual gateway (VGW), and at line level interface. In xGCP, only determination of number of active calls is supported. The dspcallcnt command was added to support this feature.

IP-IP Transcoding for H.248

VXSM functions as a transcoding gateway and provides the interworking functionality for gateways that differ in bearer capabilities to communicate with each other. The capabilities between two gateways may differ depending on the bearer properties such as Codec, packetization period, etc.,or incompatible features such as fax or modem pass through, fax relay, or DTMF relay.

When VXSM acts as a transcoding gateway a back card is not required.

The following commands were added to support this feature:

•cnfgwdsp

•dspgwdsp

The following commands were modified:

•cnfdspparam

•cnftermtype

G.723 Annex A and G.729 Annex B support for H.248

•VXSM supports VAD activation and de-activation in conjunction with the G.729 Codec and G.723 Codec, using the "annexb" and "annexa" values in fmtp attribute respectively. For the G.723 Annex A and G.729 Annex B support for H.248 feature, the following commands were added:

–cnfh248profannexab

–dsph248profannexab

–cnfh248profcodecnotation

–dsph248profcodecnotation

Metric to Report VXSM Card Availability

VXSM currently provides a CLI command to check how long the card has been in the up state.This release provides MIB support for the existing dspcduptime command that allow users of SNMP to view information about the status of the card directly on the managed agent.

The CISCO-ENTITY-FRU-CONTROL-MIB has been added to support this functionality. The card uptime value is updated in the stats upload file. During switchover, the uptime values for standalone cards are lost.

Note For redundant cards, the uptime value may vary from that of the active or standby card.

OOS and IS of VXSM Trunks at all Interface Levels

This feature allows VXSM to configure the administrative status of the path to down, even if the TDM configuration exists for a particular path or line.

Configuring Circuit Description

This enhancement allows you to configure a line or path or ds1 level description for the TDM network lines. To enable the circuit description configuration, a new parameter Circuit Identifier has been added.

The Circuit Identifier parameter is added in the following commands:

•cnfln

•cnfpath

DD and DG Package Support for IP Terminations

VXSM supports DTMF Detection (DD) and DTMF Generator (DG) package that are used by the gateways to detect the digits on both TDM and IP terminations.

The cnftermtype command is modified to supportdetection and generation of dual tone multifrequency (DTMF) feature.

The following commands are added to support this feature:

•cnfgwdsp

•dspgwdsp

New Codec Support for H.248, MGCP, and TGCP Signaling

VXSM supports the following new Codecs for H.248, MGCP, and TGCP signaling:

•Adaptive Multi-Rate (AMR) Codec

•GSM Enhanced Full Rate (GSM-EFR)

•Internet Low Bitrate Codec (iLBC)

The following features were added to support this feature:

•cnfcodecspecific - amrnb

•dspcodecspecific - amrnb

•cnfcodecspecific - ilbc

•dspcodecspecific - ilbc

The following commands were modified:

•cnfcodecparam

•dspcodecparam

•dspcodecparams

•clrcodeccnt

•dspcodeccnt

•dspdspcodecpools

Bearer Tracing for IP-IP calls

VXSM Release 5.5.00 adds support for IP-IP bearer tracing. Bearer tracing for TDM-IP calls is already supported. For the bearer tracing for IP-IP calls feature, the addbearertraceendpt command was modified.

Non-Calea to Calea VXSM Image Upgrade Support

In this release, VXSM supports graceful upgrade from Non-Calea image to Calea image. Upgrade is supported for all three call control protocols: H.248, MGCP, and TGCP.

NTE and NSE Payload Negotiation Support for H.248

VXSM supports Named Telephone Events (NTE) and Named Signaling Events (NSE) payload negotiation for H.248. This includes only the payload negotiation; events will not be negotiated in both the cases (NTE and NSE).

Resource Monitoring at VXSM

Additional parameters are now monitored at VXSM. VXSM generates traps to NMS whenever a buffer exceeds its maximum threshold capacity or falls below its minimum.

Support for T38 fallback to PCMU/PCMA

This feature supports T38 fallback to PCMU/PCMA. MGC asks VXSM to move to T.38 mode and sends the same request to another end, for instance, a SIP end. Now, for some reasons, if the SIP end does not move to T.38, the MGC asks the VXSM to fallback to PCMU/PCMA so that it can still send the FAX.

Support for SMS Tone Detection

SMS detection feature adds support for SMS traffic delivery through the voice bandwidth of an established voice session. The following commands were added to support this feature:

•cnfeventmapping - sms

•dspeventmapping - sms

Firmware Images

For each VXSM card type (OC-3/STM-1, T1/E1, or T3), two firmware images are available, namely, Non-CALEA and CALEA. When placing an order, the user must specify whether a Non-CALEA or CALEA image is required.

Both CALEA and Non-CALEA images supports three Media Gateway Control protocols, namely, H.248, MGCP, and TGCP. However, VXSM supports only one protocol at a time. The user must choose between the H.248, MGCP, and TGCP protocols when the image is first loaded from the PXM using the setrev command.

The CALEA image supports LI based on SII architecture for H.248, TGCP and MGCP protocols. The PktCable CALEA is supported only with MGCP and TGCP protocols.

VXSM supports four different Codec templates; Tandem Gateway (TGW), Tandem Gateway 2, Fixed Mobile Convergence (FMC), and Cable. The Cable template can be used only in conjunction with TGCP.

Upgrading from an Earlier VXSM Release

VXSM can be gracefully upgraded (configuration is preserved) from VXSM Release 5.3.10 or later.

Note VXSM supports upgrade of non-CALEA to CALEA firmware. But upgrade from CALEA to non-CALEA is not supported.

When loading or upgrading a boot or runtime image to a VXSM card, users must observe the following caution:

Caution If an H.248 association is active with SrvChgProfile (used in service change message) as BT_TGW in 5.3.x.x release, after graceful upgrade to 5.5.00, the association will continue to use BT_TGW, but new association(s) cannot be added with SrvChgProfile as BT_TGW.

From the 5.4.00 release onward, the BT_TGW SrvChgProfile is no longer available. All new associations must be added using either etsi_tgw or CISCO_TGW.

Prior to upgrade, user should confirm that additional termtypes (other than the defaults) have not been configured for VXSM in H.248.

Warning Many of the commands involved in loading or upgrading boot and runtime images can take several minutes to execute completely. If the user resets or otherwise disturbs the VXSM card during a loading or upgrading process, the card can easily be damaged even to the extent that it must be returned to the factory for repair.In particular:Do not reset VXSM or PXM cards manually or through commands such as resetcd or resetsysDo not save all MGX configurations with commands such as saveallcnfs.Do not toggle primary/secondary cards through commands such as switchredcd, delred Do not change the name of software image before or during the upgradeDo not change any configuration of active primary card during the upgradeTHE REAPPEARANCE OF THE COMMAND PROMPT AFTER A COMMAND IS ENTERED DOES NOT INDICATE THAT THE IMAGE LOAD OR UPGRADE HAS BEEN COMPLETED. After the execution of the burnboot, clrsmcnf, loadrev, or setrev commands, the user must execute either a dspcds or dsprev command periodically to verify that the state of the VXSM card being loaded or upgraded is either Active, Standby, or Failed. ONLY WHEN THE CARD IS DISPLAYED TO BE IN ONE OF THESE STATES IS IT SAFE TO GO TO THE NEXT STEP.If the upgrade procedure is interrupted for reasons outside the control of the user (for example, a power outage), see "Interrupted Procedure Recovery" below for instructions.

Interrupted Procedure Recovery

In the event that a VXSM software upgrade procedure is interrupted (for example, power outage), and both Primary and Secondary are stuck in 'Failed-U' state, perform the following procedure

Step 1 Execute the abortrev command:

abortrev <PrimarySlot> <NewImageRevision>

Step 2 If the primary VXSM becomes "Failed/Active" (out of Failed-U/Active"), then execute the resetcd command

resetcd <PrimarySlot>

Step 3 If the secondary VXSM becomes "Failed/Active" (out of Failed-U/Active"), then execute the resetcd command:

resetcd <SecondarySlot>

Step 4 Both primary and secondary VXSM cards should now have their original SW image and original DB

Feature Clarifications

Call Rate Performance Support

VXSM OC3 Card supports the following call rates:

•In MGCP, the maximum CPS supported is 60 (without signaling). If signaling (M3UA/IUA/RUDP) is configured, then the maximum supported CPS is 50.

•In H.248, the maximum CPS supported is 85 (without signaling). If signaling (M3UA/IUA) is configured, then the maximum supported CPS is 50.

Online Diagnostics Feature as Applied to VXSM

The online diagnostics feature as implemented on the PXM45 card is supported on VXSM. When enabled, using the PXM45 cnfdiag command, this feature performs non-intrusive diagnostics tests that use four of the VXSM G711 DSP resources.

If the user executes the VXSM dspdspcodecpools command, the resulting display shows the four G711 DSP resources being used (for diagnostics) and subtracts them from the remaining available Codecs (see example below).

mgx.3.VXSM.a > dspdspcodecpools

=====================================================================

DSP codec capacity usage

=====================================================================

Codec pool Current utilized Current available

capacity (#DSP chans) capacity (#DSP chans)

========== ===================== =====================

G711 family/HDLC 179 7885

G729/G726/T.38 family 0 3919

G723 family 0 2911

In this example, 175 G711 calls have been established along with four G711 resources used for diagnostics.

The online diagnostics feature does not reduce the maximum number of 8064 G711 DSP resources available for calls on the VXSM card. If the number of call requests on the VXSM is sufficiently high, the online diagnostic feature is disabled automatically and the four Codecs are made available for active calls.

DSP Resources Under Mixed Codec Conditions

When the same Codec is used to setup calls on the gateway the available DSP resources will be fully utilized. However when different Codecs are used to setup calls the amount of utilizable DSP resources may be limited in certain cases due to resource fragmentation.

Fragmentation is said to have occurred when the available capacities on two different DSP resources have enough available capacity to support a call of a particular Codec type but cannot support that Codec type individually.

Consider two DSP resources whose available capacity is 1 unit each making the total available capacity 2 units. However a Codec that requires 2 units cannot be supported in the system because the available capacities have been fragmented across the individual DSP resources.

The DSP allocation algorithm on VXSM does make an attempt to smooth the effects of fragmentation. Fragmentation can happen because the pattern of future calls cannot be predicted beforehand.

VXSM Management Information Base

The VXSM Management Information Base (MIB) Version 5.5 is available to users with CCO accounts who can access the MIB and VXSM software on-line at: http://www.cisco.com/kobayashi/sw-center/sw-wan.shtml

Step 1 Log on to http://www.cisco.com/kobayashi/sw-center/sw-wan.shtml

Step 2 Locate the VXSM platform (either VXSM 8880 or VXSM 8850) and click the down arrow to expand the "Select Release Level" drop down menu.

Obtaining Documentation, Obtaining Support, and Security Guidelines

For information on obtaining documentation, obtaining support, providing documentation feedback, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:

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